Electrochemically fabricated microprobes

ABSTRACT

Multilayer test probe structures are electrochemically fabricated via depositions of one or more materials in a plurality of overlaying and adhered layers. In some embodiments each probe structure may include a plurality of contact arms or contact tips that are used for contacting a specific pad or plurality of pads wherein the arms and/or tips are configured in such away so as to provide a scrubbing motion (e.g. a motion perpendicular to a primary relative movement motion between a probe carrier and the IC) as the probe element or array is made to contact an IC, or the like, and particularly when the motion between the probe or probes and the IC occurs primarily in a direction that is perpendicular to a plane of a surface of the IC. In some embodiments arrays of multiple probes are provided and even formed in desired relative position simultaneously.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/244,817, filed Oct. 6, 2005 which is a continuation of U.S. patentapplication Ser. No. 10/772,943, filed Feb. 4, 2004 which in turn claimsbenefit of U.S. Provisional Patent Application Nos. 60/445,186;60/506,015; 60/533,933, and 60/536,865 filed on Feb. 4, 2003; Sep. 24,2003; Dec. 31, 2003, and Jan. 15, 2004 respectively. All of theseapplications, including any appendices attached thereto are incorporatedherein by reference as if set forth in full herein.

FIELD OF THE INVENTION

The present invention relates generally to microprobes andelectrochemical fabrication processes (e.g. EFAB® fabrication processes)for making them and more particularly to microprobe designs.

BACKGROUND OF THE INVENTION

A technique for forming three-dimensional structures (e.g. parts,components, devices, and the like) from a plurality of adhered layerswas invented by Adam L. Cohen and is known as ElectrochemicalFabrication. It is being commercially pursued by Microfabrica Inc.(formerly MEMGen® Corporation) of Burbank, Calif. under the name EFAB™.This technique was described in U.S. Pat. No. 6,027,630, issued on Feb.22, 2000. This electrochemical deposition technique allows the selectivedeposition of a material using a unique masking technique that involvesthe use of a mask that includes patterned conformable material on asupport structure that is independent of the substrate onto whichplating will occur. When desiring to perform an electrodeposition usingthe mask, the conformable portion of the mask is brought into contactwith a substrate while in the presence of a plating solution such thatthe contact of the conformable portion of the mask to the substrateinhibits deposition at selected locations. For convenience, these masksmight be generically called conformable contact masks; the maskingtechnique may be generically called a conformable contact mask platingprocess. More specifically, in the terminology of Microfabrica Inc.(formerly MEMGen® Corporation) of Burbank, Calif. such masks have cometo be known as INSTANT MASKS™ and the process known as INSTANT MASKING™or INSTANT MASK™ plating. Selective depositions using conformablecontact mask plating may be used to form single layers of material ormay be used to form multi-layer structures. The teachings of the '630patent are hereby incorporated herein by reference as if set forth infull herein. Since the filing of the patent application that led to theabove noted patent, various papers about conformable contact maskplating (i.e. INSTANT MASKING) and electrochemical fabrication have beenpublished:

-   -   (1) A. Cohen, G. Zhang, F. Tseng, F. Mansfeld, U. Frodis and P.        Will, “EFAB: Batch production of functional, fully-dense metal        parts with micro-scale features”, Proc. 9th Solid Freeform        Fabrication, The University of Texas at Austin, p 161, Aug.        1998.    -   (2) A. Cohen, G. Zhang, F. Tseng, F. Mansfeld, U. Frodis and P.        Will, “EFAB: Rapid, Low-Cost Desktop Micromachining of High        Aspect Ratio True 3-D MEMS”, Proc. 12th IEEE Micro Electro        Mechanical Systems Workshop, IEEE, p 244, January 1999.    -   (3) A. Cohen, “3-D Micromachining by Electrochemical        Fabrication”, Micromachine Devices, March 1999.    -   (4) G. Zhang, A. Cohen, U. Frodis, F. Tseng, F. Mansfeld, and P.        Will, “EFAB: Rapid Desktop Manufacturing of True 3-D        Microstructures”, Proc. 2nd International Conference on        Integrated MicroNanotechnology for Space Applications, The        Aerospace Co., Apr. 1999.    -   (5) F. Tseng, U. Frodis, G. Zhang, A. Cohen, F. Mansfeld, and P.        Will, “EFAB: High Aspect Ratio, Arbitrary 3-D Metal        Microstructures using a Low-Cost Automated Batch Process”, 3rd        International Workshop on High Aspect Ratio MicroStructure        Technology (HARMST'99), June 1999.    -   (6) A. Cohen, U. Frodis, F. Tseng, G. Zhang, F. Mansfeld, and P.        Will, “EFAB: Low-Cost, Automated Electrochemical Batch        Fabrication of Arbitrary 3-D Microstructures”, Micromachining        and Microfabrication Process Technology, SPIE 1999 Symposium on        Micromachining and Microfabrication, September 1999.    -   (7) F. Tseng, G. Zhang, U. Frodis, A. Cohen, F. Mansfeld, and P.        Will, “EFAB: High Aspect Ratio, Arbitrary 3-D Metal        Microstructures using a Low-Cost Automated Batch Process”, MEMS        Symposium, ASME 1999 International Mechanical Engineering        Congress and Exposition, November, 1999.    -   (8) A. Cohen, “Electrochemical Fabrication (EFABTM)”, Chapter 19        of The MEMS Handbook, edited by Mohamed Gad-EI-Hak, CRC Press,        2002.    -   (9) Microfabrication—Rapid Prototyping's Killer Application”,        pages 1-5 of the Rapid Prototyping Report, CAD/CAM Publishing,        Inc., June 1999.

The disclosures of these nine publications are hereby incorporatedherein by reference as if set forth in full herein.

The electrochemical deposition process may be carried out in a number ofdifferent ways as set forth in the above patent and publications. In oneform, this process involves the execution of three separate operationsduring the formation of each layer of the structure that is to beformed:

-   -   1. Selectively depositing at least one material by        electrodeposition upon one or more desired regions of a        substrate.    -   2. Then, blanket depositing at least one additional material by        electrodeposition so that the additional deposit covers both the        regions that were previously selectively deposited onto, and the        regions of the substrate that did not receive any previously        applied selective depositions.    -   3. Finally, planarizing the materials deposited during the first        and second operations to produce a smoothed surface of a first        layer of desired thickness having at least one region containing        the at least one material and at least one region containing at        least the one additional material.

After formation of the first layer, one or more additional layers may beformed adjacent to the immediately preceding layer and adhered to thesmoothed surface of that preceding layer. These additional layers areformed by repeating the first through third operations one or more timeswherein the formation of each subsequent layer treats the previouslyformed layers and the initial substrate as a new and thickeningsubstrate.

Once the formation of all layers has been completed, at least a portionof at least one of the materials deposited is generally removed by anetching process to expose or release the three-dimensional structurethat was intended to be formed.

The preferred method of performing the selective electrodepositioninvolved in the first operation is by conformable contact mask plating.In this type of plating, one or more conformable contact (CC) masks arefirst formed. The CC masks include a support structure onto which apatterned conformable dielectric material is adhered or formed. Theconformable material for each mask is shaped in accordance with aparticular cross-section of material to be plated. At least one CC maskis needed for each unique cross-sectional pattern that is to be plated.

The support for a CC mask is typically a plate-like structure formed ofa metal that is to be selectively electroplated and from which materialto be plated will be dissolved. In this typical approach, the supportwill act as an anode in an electroplating process. In an alternativeapproach, the support may instead be a porous or otherwise perforatedmaterial through which deposition material will pass during anelectroplating operation on its way from a distal anode to a depositionsurface. In either approach, it is possible for CC masks to share acommon support, i.e. the patterns of conformable dielectric material forplating multiple layers of material may be located in different areas ofa single support structure. When a single support structure containsmultiple plating patterns, the entire structure is referred to as the CCmask while the individual plating masks may be referred to as“submasks”. In the present application such a distinction will be madeonly when relevant to a specific point being made.

In preparation for performing the selective deposition of the firstoperation, the conformable portion of the CC mask is placed inregistration with and pressed against a selected portion of thesubstrate (or onto a previously formed layer or onto a previouslydeposited portion of a layer) on which deposition is to occur. Thepressing together of the CC mask and substrate occur in such a way thatall openings, in the conformable portions of the CC mask contain platingsolution. The conformable material of the CC mask that contacts thesubstrate acts as a barrier to electrodeposition while the openings inthe CC mask that are filled with electroplating solution act as pathwaysfor transferring material from an anode (e.g. the CC mask support) tothe non-contacted portions of the substrate (which act as a cathodeduring the plating operation) when an appropriate potential and/orcurrent are supplied.

An example of a CC mask and CC mask plating are shown in FIGS. 1A-1C.FIG. 1A shows a side view of a CC mask 8 consisting of a conformable ordeformable (e.g. elastomeric) insulator 10 patterned on an anode 12. Theanode has two functions. FIG. 1A also depicts a substrate 6 separatedfrom mask 8. One is as a supporting material for the patterned insulator10 to maintain its integrity and alignment since the pattern may betopologically complex (e.g., involving isolated “islands” of insulatormaterial). The other function is as an anode for the electroplatingoperation. CC mask plating selectively deposits material 22 onto asubstrate 6 by simply pressing the insulator against the substrate thenelectrodepositing material through apertures 26 a and 26 b in theinsulator as shown in FIG. 1B. After deposition, the CC mask isseparated, preferably non-destructively, from the substrate 6 as shownin FIG. 1C. The CC mask plating process is distinct from a“through-mask” plating process in that in a through-mask plating processthe separation of the masking material from the substrate would occurdestructively. As with through-mask plating, CC mask plating depositsmaterial selectively and simultaneously over the entire layer. Theplated region may consist of one or more isolated plating regions wherethese isolated plating regions may belong to a single structure that isbeing formed or may belong to multiple structures that are being formedsimultaneously. In CC mask plating as individual masks are notintentionally destroyed in the removal process, they may be usable inmultiple plating operations.

Another example of a CC mask and CC mask plating is shown in FIGS.1D-1F. FIG. 1D shows an anode 12′ separated from a mask 8′ that includesa patterned conformable material 10′ and a support structure 20. FIG. 1Dalso depicts substrate 6 separated from the mask 8′. FIG. 1E illustratesthe mask 8′ being brought into contact with the substrate 6. FIG. 1Fillustrates the deposit 22′ that results from conducting a current fromthe anode 12′ to the substrate 6. FIG. 1G illustrates the deposit 22′ onsubstrate 6 after separation from mask 8′. In this example, anappropriate electrolyte is located between the substrate 6 and the anode12′ and a current of ions coming from one or both of the solution andthe anode are conducted through the opening in the mask to the substratewhere material is deposited. This type of mask may be referred to as ananodeless INSTANT MASK™ (AIM) or as an anodeless conformable contact(ACC) mask.

Unlike through-mask plating, CC mask plating allows CC masks to beformed completely separate from the fabrication of the substrate onwhich plating is to occur (e.g. separate from a three-dimensional (3D)structure that is being formed). CC masks may be formed in a variety ofways, for example, a photolithographic process may be used. All maskscan be generated simultaneously, prior to structure fabrication ratherthan during it. This separation makes possible a simple, low-cost,automated, self-contained, and internally-clean “desktop factory” thatcan be installed almost anywhere to fabricate 3D structures, leaving anyrequired clean room processes, such as photolithography to be performedby service bureaus or the like.

An example of the electrochemical fabrication process discussed above isillustrated in FIGS. 2A-2F. These figures show that the process involvesdeposition of a first material 2 which is a sacrificial material and asecond material 4 which is a structural material. The CC mask 8, in thisexample, includes a patterned conformable material (e.g. an elastomericdielectric material) 10 and a support 12 which is made from depositionmaterial 2. The conformal portion of the CC mask is pressed againstsubstrate 6 with a plating solution 14 located within the openings 16 inthe conformable material 10. An electric current, from power supply 18,is then passed through the plating solution 14 via (a) support 12 whichdoubles as an anode and (b) substrate 6 which doubles as a cathode. FIG.2A, illustrates that the passing of current causes material 2 within theplating solution and material 2 from the anode 12 to be selectivelytransferred to and plated on the cathode 6. After electroplating thefirst deposition material 2 onto the substrate 6 using CC mask 8, the CCmask 8 is removed as shown in FIG. 2B. FIG. 2C depicts the seconddeposition material 4 as having been blanket-deposited (i.e.non-selectively deposited) over the previously deposited firstdeposition material 2 as well as over the other portions of thesubstrate 6. The blanket deposition occurs by electroplating from ananode (not shown), composed of the second material, through anappropriate plating solution (not shown), and to the cathode/substrate6. The entire two-material layer is then planarized to achieve precisethickness and flatness as shown in FIG. 2D. After repetition of thisprocess for all layers, the multi-layer structure 20 formed of thesecond material 4 (i.e. structural material) is embedded in firstmaterial 2 (i.e. sacrificial material) as shown in FIG. 2E. The embeddedstructure is etched to yield the desired device, i.e. structure 20, asshown in FIG. 2F.

Various components of an exemplary manual electrochemical fabricationsystem 32 are shown in FIGS. 3A-3C. The system 32 consists of severalsubsystems 34, 36, 38, and 40. The substrate holding subsystem 34 isdepicted in the upper portions of each of FIGS. 3A-3C and includesseveral components: (1) a carrier 48, (2) a metal substrate 6 onto whichthe layers are deposited, and (3) a linear slide 42 capable of movingthe substrate 6 up and down relative to the carrier 48 in response todrive force from actuator 44. Subsystem 34 also includes an indicator 46for measuring differences in vertical position of the substrate whichmay be used in setting or determining layer thicknesses and/ordeposition thicknesses. The subsystem 34 further includes feet 68 forcarrier 48 which can be precisely mounted on subsystem 36.

The CC mask subsystem 36 shown in the lower portion of FIG. 3A includesseveral components: (1) a CC mask 8 that is actually made up of a numberof CC masks (i.e. submasks) that share a common support/anode 12, (2)precision X-stage 54, (3) precision Y-stage 56, (4) frame 72 on whichthe feet 68 of subsystem 34 can mount, and (5) a tank 58 for containingthe electrolyte 16. Subsystems 34 and 36 also include appropriateelectrical connections (not shown) for connecting to an appropriatepower source for driving the CC masking process.

The blanket deposition subsystem 38 is shown in the lower portion ofFIG. 3B and includes several components: (1) an anode 62, (2) anelectrolyte tank 64 for holding plating solution 66, and (3) frame 74 onwhich the feet 68 of subsystem 34 may sit. Subsystem 38 also includesappropriate electrical connections (not shown) for connecting the anodeto an appropriate power supply for driving the blanket depositionprocess.

The planarization subsystem 40 is shown in the lower portion of FIG. 3Cand includes a lapping plate 52 and associated motion and controlsystems (not shown) for planarizing the depositions.

Another method for forming microstructures from electroplated metals(i.e. using electrochemical fabrication techniques) is taught in U.S.Pat. No. 5,190,637 to Henry Guckel, entitled “Formation ofMicrostructures by Multiple Level Deep X-ray Lithography withSacrificial Metal layers”. This patent teaches the formation of metalstructure utilizing mask exposures. A first layer of a primary metal iselectroplated onto an exposed plating base to fill a void in aphotoresist, the photoresist is then removed and a secondary metal iselectroplated over the first layer and over the plating base. Theexposed surface of the secondary metal is then machined down to a heightwhich exposes the first metal to produce a flat uniform surfaceextending across the both the primary and secondary metals. Formation ofa second layer may then begin by applying a photoresist layer over thefirst layer and then repeating the process used to produce the firstlayer. The process is then repeated until the entire structure is formedand the secondary metal is removed by etching. The photoresist is formedover the plating base or previous layer by casting and the voids in thephotoresist are formed by exposure of the photoresist through apatterned mask via X-rays or UV radiation.

Electrochemical Fabrication provides the ability to form prototypes andcommercial quantities of miniature objects, parts, structures, devices,and the like at reasonable costs and in reasonable times. In fact,Electrochemical Fabrication is an enabler for the formation of manystructures that were hitherto impossible to produce. ElectrochemicalFabrication opens the spectrum for new designs and products in manyindustrial fields. Even though Electrochemical Fabrication offers thisnew capability and it is understood that Electrochemical Fabricationtechniques can be combined with designs and structures known withinvarious fields to produce new structures, certain uses forElectrochemical Fabrication provide designs, structures, capabilitiesand/or features not known or obvious in view of the state of the art.

A need exists in various fields for miniature devices having improvedcharacteristics, reduced fabrication times, reduced fabrication costs,simplified fabrication processes, and/or more independence betweengeometric configuration and the selected fabrication process. A needalso exists in the field of miniature (i.e. mesoscale and microscale)device fabrication for improved fabrication methods and apparatus.

SUMMARY OF THE INVENTION

Objects and advantages of various aspects of the invention will beapparent to those of skill in the art upon review of the teachingsherein. The various aspects of the invention, set forth explicitlyherein or otherwise ascertained from the teachings herein, may addressone or more of the above objects alone or in combination, oralternatively may address some other object of the invention ascertainedfrom the teachings herein. It is not necessarily intended that allobjects be addressed by any single aspect of the invention even thoughthat may be the case with regard to some aspects.

In a first aspect of the invention, a probe device for testingintegrated circuits, including: a bridging element; a plurality ofcontact arms, each having a first end and a second end, where the secondend of each connects to the bridging element and the first end of eachis configured to contact a pad of an integrated circuit and wherein thearms are configured to scrub the surface of the pad as contact betweenthe probe and the pad is made.

In a second aspect of the invention, a probe device for testingintegrated circuits, including: a bridging element; a plurality ofcontact arms, each having a first end and a second end, where the secondend of each connects to the bridging element and the first end of eachis configured to contact a pad of an integrated circuit and wherein atleast one of the arms or the bridging element is configured to providecompliance between the probe and the pad as contact is made.

In a third aspect of the invention, a probe device for testingintegrated circuits, including: a compliant structure; a bridgingelement adhered to a compliant structure; a plurality of contact arms,each having a first end and a second end, where the second end of eachconnects to the bridging element and the first end of each is configuredto contact a pad of an integrated circuit and wherein at least one ofthe arms or the bridging element is configured to provide compliancebetween the probe and the pad as contact is made.

Further aspects of the invention will be understood by those of skill inthe art upon reviewing the teachings herein. Other aspects of theinvention may involve combinations of the above noted aspects of theinvention. Other aspects of the invention may involve methods forforming the probe devices of the aspects noted above. Other aspects mayinvolve apparatus that can be used in implementing one or more of themethod aspects of the invention. These other aspects of the inventionmay provide various combinations of the aspects presented above as wellas provide other configurations, structures, functional relationships,and processes that have not been specifically set forth above.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1C schematically depict side views of various stages of a CCmask plating process, while FIGS. 1D-1G schematically depict a sideviews of various stages of a CC mask plating process using a differenttype of CC mask.

FIGS. 2A-2F schematically depict side views of various stages of anelectrochemical fabrication process as applied to the formation of aparticular structure where a sacrificial material is selectivelydeposited while a structural material is blanket deposited.

FIGS. 3A-3C schematically depict side views of various examplesubassemblies that may be used in manually implementing theelectrochemical fabrication method depicted in FIGS. 2A-2F.

FIGS. 4A-4I schematically depict the formation of a first layer of astructure using adhered mask plating where the blanket deposition of asecond material overlays both the openings between deposition locationsof a first material and the first material itself.

FIG. 5 illustrates a probe of a first embodiment that includes twocontact arms/elements that have an outward taper.

FIG. 6 illustrates a second embodiment of a probe wherein the probeincludes four contact elements that taper in an outward direction.

FIG. 7 illustrates a probe of a third embodiment that includes twocontact arms/elements that have an inward taper.

FIG. 8 illustrates a fourth embodiment of a probe wherein the probeincludes four contact elements that taper in an outward direction.

FIGS. 9A and 9B depict respectively a side view and a perspective viewof a probe having three arm/contact elements.

FIG. 10 depicts a perspective view of another probe embodiment where theprobe has two contact arms with each have a small curvature.

FIG. 11 depicts a perspective view of another probe embodiment where theprobe has four contact arms with each have a small curvature.

FIG. 12 illustrates a probe of another embodiment where the probeincludes two contact arms/elements that have an outward taper and aconformable or compressible element.

FIG. 13 illustrates a probe of a first embodiment that includes twocontact arms/elements that have an outward taper and where itadditionally includes a conformable element between the arms and abridging element.

FIG. 14 depicts a further embodiment of a probe wherein the probe issimilar to that of the embodiment of FIG. 12 with the exception that theprobe additionally includes a drive shaft that forces a pair of pushingelements to cause the contact arms to separate.

FIG. 15 depicts and embodiment similar to that of FIG. 14 however withthe arms taking on the configuration of the embodiment of FIG. 13.

FIG. 16 depicts a further alternative embodiment where a probe includesa shaft that can move independently of the movement of a bridge elementsuch that both inward and outward motion of the contact arms can be madeto occur.

FIG. 17 depicts a further alternative embodiment where a probe includesa shaft to which elements are attached that may be used to pull thecontact arms inward.

FIG. 18 depicts a further alternative embodiment which is similar to theembodiment of FIG. 17 with the exception that the contact arms have aninward slant.

FIG. 19 depicts a side view of a probe with two joint/contact positionshighlighted.

FIGS. 20A-20D depict side views of four exemplarily joint/contactconfigurations for an arm and a pushing rod.

FIGS. 21A-21D depict side views of four exemplarily joint/contactconfigurations for a shaft and a pushing rod.

FIG. 22 depicts a perspective view of a cut through a bellows type probeelement of another embodiment of the invention.

FIG. 23 depicts a perspective view of an array of probes mounted to asubstrate.

FIGS. 24A and 24B depict a perspective and top view, respectively of amultiple contact element microprobe according to another embodiment ofthe invention.

FIG. 25 depicts a side view of a multiple contact element probe (as cutthrough its center) according to another embodiment of the invention.

FIG. 26 depicts a side view of an alternative probe (or possibly probetip configuration) which includes two contact tips.

FIGS. 27A-27C depict a side view and two bottom views of a cylindricalprobe structure that includes top and bottom rings connected by aplurality of non-vertical extending elements.

FIG. 28 depicts a perspective view of a portion of a probe bridging ringand two contact tips located on arms extending laterally from thebridging ring.

FIGS. 29A-29B depict side views of bridging rings or disks with aplurality of tips located on arms extending both laterally andvertically from the bridging.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

FIGS. 1A-1G, 2A-2F, and 3A-3C illustrate various features of one form ofelectrochemical fabrication that are known. Other electrochemicalfabrication techniques are set forth in the '630 patent referencedabove, in the various previously incorporated publications, in variousother patents and patent applications incorporated herein by reference,still others may be derived from combinations of various approachesdescribed in these publications, patents, and applications, or areotherwise known or ascertainable by those of skill in the art from theteachings set forth herein. All of these techniques may be combined withthose of the various embodiments of various aspects of the invention toyield enhanced embodiments. Still other embodiments may be derived fromcombinations of the various embodiments explicitly set forth herein.

FIGS. 4A-4I illustrate various stages in the formation of a single layerof a multi-layer fabrication process where a second metal is depositedon a first metal as well as in openings in the first metal where itsdeposition forms part of the layer. In FIG. 4A, a side view of asubstrate 82 is shown, onto which patternable photoresist 84 is cast asshown in FIG. 4B. In FIG. 4C, a pattern of resist is shown that resultsfrom the curing, exposing, and developing of the resist. The patterningof the photoresist 84 results in openings or apertures 92(a)-92(c)extending from a surface 86 of the photoresist through the thickness ofthe photoresist to surface 88 of the substrate 82. In FIG. 4D, a metal94 (e.g. nickel) is shown as having been electroplated into the openings92(a)-92(c). In FIG. 4E, the photoresist has been removed (i.e.chemically stripped) from the substrate to expose regions of thesubstrate 82 which are not covered with the first metal 94. In FIG. 4F,a second metal 96 (e.g., silver) is shown as having been blanketelectroplated over the entire exposed portions of the substrate 82(which is conductive) and over the first metal 94 (which is alsoconductive). FIG. 4G depicts the completed first layer of the structurewhich has resulted from the planarization of the first and second metalsdown to a height that exposes the first metal and sets a thickness forthe first layer. In FIG. 4H the result of repeating the process stepsshown in FIGS. 4B-4G several times to form a multi-layer structure areshown where each layer consists of two materials. For most applications,one of these materials is removed as shown in FIG. 4I to yield a desired3-D structure 98 (e.g. component or device).

The various embodiments, alternatives, and techniques disclosed hereinmay be combined with or be implemented via electrochemical fabricationtechniques. Such combinations or implementations may be used to formmulti-layer structures using a single patterning technique on all layersor using different patterning techniques on different layers. Forexample, different types of patterning masks and masking techniques maybe used or even techniques that perform direct selective depositions maybe used without the need for masking. For example, conformable contactmasks may be used during the formation of some layers or during someselective deposition or etching operations while non-conformable contactmasks may be used in association with the formation of other layers orduring other selective deposition or etching operations. Proximity masksand masking operations (i.e. operations that use masks that at leastpartially selectively shield a substrate by their proximity to thesubstrate even if contact is not made) may be used, and adhered masksand masking operations (masks and operations that use masks that areadhered to a substrate onto which selective deposition or etching is tooccur as opposed to only being contacted to it) may be used.

FIG. 5 illustrates a probe 202 that includes two contact arms 204(a) and204(b) that are connected by a bridge element 206, which in turnconnects to a rod 208. The rod 208 forms part of or connects to the restof a testing system which may include positioning elements andconnections or components for performing electrical tests of a circuitpad to which elements 204(a) and 204(b) will contact. Probe 202 will bedriven to contact a pad (not shown) by moving it vertically in thedirection of arrow 212. As the pad is contacted the vertical motion ofthe probe will be translated into horizontal movement of tips 214(a) and214(b) which will result in a scrubbing of the pad surface which willtend to remove any dielectric coating on the pad or on the probe tips,thereby allowing electrical contact to be made. As contact with the padis made, tips 214(a) and 214(b) will spread in the direction indicatedby arrow 216.

Various alternatives of the embodiment of FIG. 5 are possible. In somealternative embodiments, rod 208 may be excluded in favor a verticallycompliant structure or other structural element. In some alternativeembodiments the bridge element 206 may be a multilayer structure whichmay be rigid or compliant. In some alternative embodiments, contactelements 214(a) and 214(b) may be formed from a different material thanthat forming other parts of arms 204(a) and 204(b). In still otheralternative embodiments, contact elements 214(a) and 214(b) may beformed in a different process than that used to form other portions ofthe probe elements. In some embodiments, the probe 202 may actually onlybe a portion of a larger probe design which includes compliant regions,shields, or the like (e.g. probe 202 may be considered a multi-layerprobe tip structure as opposed to an entire probe). In some alternativeembodiments additional arm-like elements and contact elements may used.In still other embodiments, the various layer steps in the structure mayeach be made of multiple layers, the layer thickness used may be muchsmaller than the structural height and/or the layers may offset in amore uniform manner such that the discontinuities between layers is lessnoticeable. In some alternative embodiments a smaller number of layersmay be used or a larger number of layers. Various elements of thesealternative embodiments may be the basis of alternatives to the variousother embodiments set forth hereafter and/or may combined with oneanother or with other alternatives to form other embodiments.

FIG. 6 illustrates an alternative embodiment where the probe 222includes four contact elements 224(a)-224(d), along with bridge element226 and rod 228. To contact a pad to be tested, the probe is moved inthe direction of arrow 232, and as contact with the pad is made arms224(a) and 224(b) move radially outward in the direction shown by arrow236 while elements 224(c) and 224(d) spread outward in the directionshown by arrow 238.

FIG. 7 shows another alternative embodiment for a probe device whichincludes two contact arms 242(a) and 242(b) connected to a bridgeelement 246 and a support and movement rod 248. The probe is movedvertically to contact a pad (not shown) to be tested where the movementis in the direction indicated by arrow 252. As the pad is contacted thetwo contact arms 242(a) and 242(b) slide towards each other in thedirections indicated by arrows 254(a) and 254(b).

FIG. 8 shows a further alternative embodiment where the probe is similarto that of FIG. 7 with the exception that two additional probe arms areincluded.

FIG. 9A depicts a side view of a probe that includes contact arms 282(a)and 282(b). The contact arms are directed in opposing directions and areoffset from one another (as can be better seen in FIG. 9B) so that theydo not contact one another. The contact arms join a common bridgeelement 286 which in turn connects to a rod 288 which can be used tomove the probe vertically up and down to bring it into and away fromcontact with an electrical pad to be probed. As the probe is moveddownward and it contacts an electrical pad to be tested (not shown), arm282 scrubs in the direction indicated by arrow 292(a) while arm 282(b)scrubs in the direction shown by arrow 292(b).

A perspective view of the structure of FIG. 9A is shown in FIG. 9B whereit can be seen that the probe includes three contact arms 282(a), 282(b)and 282(c). As the probe is moved in the direction indicated by arrow294 and contact is made with the pad to be tested, arms 282(a), 282(b)and 282(c) move in the directions indicated by arrows 292(a), 292(b),and 292(c) respectively.

FIGS. 10 and 11 illustrate a further embodiment of probe elements. Theprobe of FIG. 10 is shown as having two arms 302(a) and 302(b) connectedby a bridge element 306 which in turn is connected to rod element 308.As the arm elements 302(a) and 302(b) have both an inward and outwardbend they provide some amount of compliance as a pad is contacted butthey provide little or no scrapping or scrubbing of the pad surfaceduring at after contact is made. As such, a probe of this type may havemore difficulty in penetrating any dielectric coating located on the padsurface. Some scrubbing may be provided in embodiments where the inwardand outward curvatures are of different magnitudes (e.g. when thecontact regions are not located directly below the regions where thearms join the bridge element). To assist in the scrubbing process rod308 may be made to undergo slight movement or vibration in a horizontaldirection thereby causing the two contact arms to scrub the surface freeof any conductivity inhibiting dielectric. Such vibration may be of anyappropriate frequency and magnitude which is sufficient to causesuccessful scrubbing without causing damage to the electrical componentbeing tested or the probe elements themselves.

FIG. 11 illustrates another alternative embodiment where the probe issimilar to that of FIG. 10 with the exception that four contact arms arepresent instead of two.

FIG. 12 depicts another alternative embodiment with contact arms 204(a)and 204(b) that are similar to those of FIG. 5. The probe includes a rod208 and a bridge element 206 as did the embodiment of FIG. 5. HoweverFIG. 12 additionally includes, disposed between bridge 206 and arms204(a) and 204(b), a compliant member 210. As the probe is made tocontact a pad (not shown), at the lower surfaces of arms 204(a) and204(b), the compliant element 210 compresses. This compression reducesthe risk of arms 204(a) and 204(b) damaging the electronic component, italso ensures a steady contact force between arms 204(a) and 204(b) andthe pad (not shown), and allows for any vertical displacement necessaryto bring an array of contact elements into contacting position withtheir respective pads. In other embodiments different width to heightaspect ratios may be used, additional arms and associated compliantstructures may be added, and/or the bridging element or a secondarybridging element may be located at the bottom and/or in the middle ofthe compliant portion of the structure (e.g. if the compliant structuretook the form of discs separated by large diameter rings and smalldiameters rings or rods—bellows-like structures).

FIG. 13 depicts an additional alternative embodiment with contact armssimilar to those shown in FIG. 7 with the addition of a compliantelement 240 located between contact arms 242(a) and 242(b) and bridgeelement 246.

FIG. 14 depicts a probe having arms 204(a) and 204(b), a compliantmember 210, a bridging element 206, and a rod 208 which are similar tothose depicted in the embodiment of FIG. 12. The embodiment of FIG. 14additionally includes a shaft 402 which abuts bridge element 206 andpushing elements 404(a) and 404(b). As rod 208 is driven downwardforcing the probe 400 against a pad to be tested, compliant member 210compresses thereby driving shaft 408 downward which in turn forcespushing elements 404(a) and 404(b) to assume more horizontal positionswhich force the separation of arms 204(a) and 204(b). This in turnforces the tips 424(a) and 424(b) of the arms to scrub the surface ofthe pad thereby enhancing the electrical contact between the probe andthe pad.

FIG. 15 depicts an additional alternative embodiment having arms, abridging element, and a rod similar to that of FIG. 13 as well as acompliant element similar to but with a slightly different configurationthan that shown in FIG. 13 and where the embodiment includes a shaft andpushing elements similar to those of the embodiment of FIG. 14.

FIG. 16 depicts a further alternative embodiment where the shaft 502 iscapable of separate movement relative to bridging element 506 such thatrelative upward and downward movement of shaft 502 can cause eitherinward or outward movement, respectively, of the arms in the directionsindicated by arrows 528(a) and 528(b).

FIG. 17 depicts a further embodiment similar to that of FIG. 14, withthe exception that it does not include pushing elements that cause thearms to split apart upon making contact with a pad to be tested.Instead, in this embodiment, pulling elements 606(a) and 606(b) connectthe shaft 624 to the arms 602(a) and 602(b). In this embodiment, theconnecting arms extend horizontally such that any downward movement ofthe shaft causes a deflection of the pulling elements that in turn causethe separation between the ends of the arms to decrease. In otherembodiments, the pulling elements may take on other configurations (e.g.a downward slant toward the shaft).

The embodiment of FIG. 18 is similar to that of FIG. 17 with theexception that the arms point inward instead of outward.

FIGS. 19-21 depict various examples of joint/contact possibilities thatmay exist between the arms and the separating elements (i.e. in theregions encircled by element 19) and between the separating elements andthe shaft (as indicated by element 20).

FIGS. 20A and 21A indicate that the connections may be of a fixed naturesuch that movement occurs by flexing of the separating elements and/orthe shaft and/or the arms. FIGS. 20B and 21B indicate that thepositioning of the elements may be by having them abut against oneanother. FIGS. 20C and 21C indicate that the positioning/connection maybe via a hinge like structure (such a structure can be built directlyusing electrochemical fabrication by leaving a small region ofsacrificial material between the moving elements so that after releasethe elements can move relative to one another). FIGS. 20D and 21Dindicate that the elements may be moveably connected by a ball andsocket-type joint (such a structure can be built directly usingelectrochemical fabrication by leaving a small region of sacrificialmaterial between the moving elements so that after release the elementscan move relative to one another).

In various alternative embodiments the positioning/connecting elementsmay take on various other forms. In still other embodiments differenttypes of joints/contacts may be used in the shaft-to-pushrod region andin the pushrod-to-arm region.

In still other embodiments, compliant members may be used that havedifferent configurations than the specific spring-like elements shown.In still other embodiments different numbers of arms may be used; thearms may be extended at different angles; they may include differentnumbers of layer elements; the arms and separating elements may take onother configurations that result in non-radial scrubbing of the padsurface, and the like. In still other embodiments, horizontal movementor vibration of the contact arms/elements may be used to enhancescrubbing.

The configuration of the tips of the arms that contact the pad to betested (i.e. the contact region of the arms) may take on differentconfigurations than those illustrated. For example, the tips (i.e.contact region) of the arms may be narrower than the width of the armsin a direction perpendicular to a direction used for scrubbing. The tipsmay be shorter than a length of the arms in a direction parallel to thedirection used for scrubbing. The contact region of the arm may beformed from a different material than that used to form the bulk of thearms. The contact region of the arms may be located relative to the restof the arm such that during movement of the arms (during a scrubbingmotion), the contact region experiences a desired force distributionthat, for example, may cause the orientation of the contact region tobecome non-parallel to the plane of the pad being contacted. Such achange in orientation may cause a desired biting or scrapping effectbetween the pad and the contact region such that the effectiveness ofscrubbing (i.e. breaking through any oxide or other dielectric layer) isenhanced.

In still other embodiments, the positioning of the arms relative to anycompliance member and more particularly relative to any movement of thecompliance member may be selected so as to cause the contact region ofthe arms to take on an orientation that is non-parallel to that of a padbeing contacted. The orientation may be such that the leading edge ofthe contact region (e.g. edge of the layer forming the contact region)digs into the pad or such that a desired side edge or trailing edge ofthe contact region digs into the pad so as to cause an enhancedscrubbing effect.

In some preferred embodiments the probe structures depicted may beformed using electrochemical fabrication techniques of the contact mask(e.g. conformable or non-conformable type) or bonded (e.g. adhered) masktype (e.g. via through mask plating using patterned photoresist masks asselective electroplating patterns). In some embodiments arrays of probesmay be formed simultaneously using electrochemical fabricationtechniques. In still other embodiments the rods and possibly the bridgeelements and parts of the arms may be part of a central conductor ofcoaxial transmission lines which helps minimize signal loss.

In some embodiments the thickness of individual layers forming amicroprobe may be much thinner than the overall height and/or width ofthe microprobe component in which case sloping elements of the probe maytake on a smooth or continuous appearance. This is illustrated in themicroprobes structures of FIGS. 22-25.

In some embodiments contact arms (e.g. the portion of a probe that isconnected to contact regions) may move relative to one another to allowscrubbing or even to cause scrubbing to occur. In some embodiments, thearms of the probe may be relatively short compared to the height of aconformable portion of the probe element. An example of such a probe isillustrated in FIG. 22 where the probe comprises a bridging element 624which connects to arms 622-1 and 622-2 and where the bridging elementincludes a compressible structure which provides compliance as the probeand pad make contact. In some embodiments, arms 622-1 and 622-2 may havemounted on their distal, or contact, regions tips configurations. Thesetip configurations may be such that during compression of the compliantstructure, as contact is being established, a relative horizontalmovement of the tips occurs that causes a scrubbing between at least oneof the tips and the pad to occur. In still other embodiments a largenumber of probes may be formed on or attached to a single supportstructure to form a probe array of desired configuration. An example ofsuch a probe array is illustrated in FIG. 23. The probe array of FIG. 23may be obtained by either electrochemical fabrication of the probes 632onto substrate 642 or the attachment of the probes to the substrateafter formation.

In some embodiments conformable portions of a probe element havingmultiple arms may be associated with each individual arm. An example ofsuch a probe is illustrated in FIGS. 24A and 24B. The probe includes abridging element 706, and compliant elements 704 which form the upperportion of each of six arms 702-1 to 702-6 (of which only 4 are shown).

FIG. 25 depicts a side view of a probe element formed with layers whichare thin compared to the overall height 750 of the probe element wherethe probe has two arms 752, connected to a bridging element 756 viacompliant (i.e. compressible) structures 754. The compressible structure754 may be a single structure that functions as part of the bridgingelement or they may be individual structures that function as part ofeach arm. A central drive shaft 758 is lowered as the structures 754compresses in response to the probe being driven against the pad whichin turn causes inner most ends 762 of the two transfer elements 764 tomove downward which in turn causes the transfer elements to spread arms752 outward so as to cause scrubbing of their contact tips 766 againstthe pad.

FIG. 26 provides a probe configuration 780 that includes a shaft 778that offers little compliance but an ability to cause scrubbing of acontact pad as the two probe tip elements 782(a) and 782(b) make contactand then are forced slightly apart as compression causes bridgingelement 784 to flex. In some embodiments, the amount of stress to whichbridging element 784 is subjected is preferably less than that whichwill result in plastic deformation of the element. In situations wheremore compliance is desired the probe configuration of FIG. 26 mayreplace shaft 778 with a more compliant structural element or group ofelements. In some alternative embodiments the bridging element may besymmetric in design and one or more additional arms and tips may beadded to it. In some alternative embodiments, the bridging element maytake on a more curved (as opposed to angular) configuration. In someembodiments, the bridging element may curve downward with the tipsextending a sufficient distance to allow contact to the pad without theshaft contacting the pad. In some embodiments, the tips may be formed ofthe same material as the bridging element while in other embodimentsthey may be of a different material. In some embodiments, the tips maybe formed in such a way so that they have tapped configurations as shownor they may take on other configurations. In some embodiments, the shaftor other structural element may contact the bridging element along arelatively straight portion of the bridging element while in otherembodiments, contact may be made at a transitional (e.g. angled orcurved portion of the bridging element.

FIGS. 27A-27C provide side views of a cylindrical probe structure with atop ring 792 and a bottom ring 794 jointed by arms 796(a)-796(d) thatextend from the perimeter of one ring to the perimeter of the other ringbut not in a completely vertical manner such that when the two rings areplaced in compression the rings will experience a rotational force. Oneof the rings may be fixed to a substrate (e.g. a space transformer),other structural elements such as a structure with a desired amount ofcompliance, or the like while the other ring has one or more probe tipelements 798(a) and 798(b) extending from it as shown in the side viewof FIG. 27B and in the bottom views of FIGS. 27B and 27C. As indicatedin FIG. 27C, the probe tip need not take on a point like configurationbut instead may have an elongated configuration or some otherconfiguration.

FIG. 28 provides ring element 802 that acts as a bridge element for twoprobe tips 804(a) and 804(b). The ring element that may be located atthe end of various probe structures (not shown, e.g. compliantstructures and the like). As shown, the ring has extending from it twolateral extending arms 806(a) and 806(b) on the distal ends of whichprobe tip elements 804(a) and 80(b) are located. As the ring makescontact with a pad (not shown) the lateral extending cantilever armsbend causing a change in the lateral separation of the probe tips thischange in separation may translate into a lateral scrubbing actionbetween at least one of the probe tips and the pad. In otherembodiments, more arms and tips may extend from the rings, the rings maytake on other configurations (e.g. square, rectangular, oval, non-closedconfigurations and the like), the tips may be formed as multi-layeredstructures or tapered structures, and/or the arms may not be completedlateral extending structures but may be formed as multilayer structuresof any desired configuration (see FIGS. 29A and 29B). FIGS. 29A and 29Bdepict side views of ring-like or disc-like structures 810 where aplurality of arms 812(a)-812(h) extend out of the plane of the ring ordisc with tips 814(a)-814(h) respectively located thereon. Whencompression is applied to the tips, each will undergo a horizontal aswell as vertical displacement that will produce a scrubbing motion. InFIG. 29A, the tips will undergo a lateral motion that moves them closertogether, while in other embodiments (e.g. when the left right armconfigurations are reversed), the displacement will cause the tips tomove further apart.

Some embodiments may employ diffusion bonding or the like to enhanceadhesion between successive layers of material. Various teachingsconcerning the use of diffusion bonding in electrochemical fabricationprocess is set forth in U.S. Patent Application No. 60/534,204 which wasfiled Dec. 31, 2003 by Cohen et al. which is entitled “Method forFabricating Three-Dimensional Structures Including Surface Treatment ofa First Material in Preparation for Deposition of a Second Material” andwhich is hereby incorporated herein by reference as if set forth infull.

Further teaching about microprobes and electrochemical fabricationtechniques are set forth in a number of U.S. patent applications whichwere filed Dec. 31, 2003. These Filings include: (1) U.S. PatentApplication No. 60/533,975 by Kim et al. and which is entitled“Microprobe Tips and Methods for Making”; (2) U.S. Patent ApplicationNo. 60/533,947 by Kumar et al. and which is entitled “Probe Arrays andMethod for Making”; (3) U.S. Patent Application No. 60/533,948 by Cohenet al. and which is entitled “Electrochemical Fabrication Method forCo-Fabricating Probes and Space Transformers”; and (4) U.S. PatentApplication No. 60/533,897 by Cohen et al. and which is entitled“Electrochemical Fabrication Process for Forming MultilayerMultimaterial Microprobe structures”. These patent filings are eachhereby incorporated herein by reference as if set forth in full herein.

Teachings concerning the formation of structures on dielectricsubstrates and/or the formation of structures that incorporatedielectric materials into the formation process and possibility into thefinal structures as formed are set forth in a number of patentapplications filed on Dec. 31, 2003. The first of these filings is U.S.Patent Application No. 60/534,184, which is entitled “ElectrochemicalFabrication Methods Incorporating Dielectric Materials and/or UsingDielectric Substrates”. The second of these filings is U.S. PatentApplication No. 60/533,932, which is entitled “ElectrochemicalFabrication Methods Using Dielectric Substrates”. The third of thesefilings is U.S. Patent Application No. 60/534,157, which is entitled“Electrochemical Fabrication Methods Incorporating DielectricMaterials”. The fourth of these filings is U.S. Patent Application No.60/533,891, which is entitled “Methods for Electrochemically FabricatingStructures Incorporating Dielectric Sheets and/or Seed layers That ArePartially Removed Via Planarization”. A fifth such filing is U.S. PatentApplication No. 60/533,895, which is entitled “ElectrochemicalFabrication Method for Producing Multi-layer Three-DimensionalStructures on a Porous Dielectric”. These patent filings are each herebyincorporated herein by reference as if set forth in full herein.

Various other embodiments of the present invention exist. Some of theseembodiments may be based on a combination of the teachings herein withvarious teachings incorporated herein by reference. Some embodiments maynot use any blanket deposition process and/or they may not use aplanarization process. Some embodiments may involve the selectivedeposition of a plurality of different materials on a single layer or ondifferent layers. Some embodiments may use selective depositionprocesses or blanket deposition processes on some layers that are notelectrodeposition processes. Some embodiments may use nickel as astructural material while other embodiments may use different materials.Some embodiments may use copper as the structural material with orwithout a sacrificial material. Some embodiments may remove asacrificial material while other embodiments may not. Some embodimentsmay employ mask based selective etching operations in conjunction withblanket deposition operations. Some embodiments may form structures on alayer-by-layer basis but deviate from a strict planar layer on planarlayer build up process in favor of a process that interlacing materialbetween the layers. Examples of such build processes are disclosed inU.S. application Ser. No. 10/434,519, filed on May 7, 2003, entitled“Methods of and Apparatus for Electrochemically Fabricating StructuresVia Interlaced Layers or Via Selective Etching and Filling of Voids”.This application and the other applications, patents, and publicationsset forth herein are each incorporated herein by reference as if setforth in full.

In view of the teachings herein, many further embodiments, alternativesin design and uses of the instant invention will be apparent to those ofskill in the art. As such, it is not intended that the invention belimited to the particular illustrative embodiments, alternatives, anduses described above but instead that it be solely limited by the claimspresented hereafter.

1. A probe device for testing integrated circuits, comprising: a bridging element; a plurality of contact arms, each having a first end and a second end, where the second end of each connects to the bridging element and the first end of each is configured to contact a pad of an integrated circuit and wherein the arms are configured to scrub a surface of the pad as contact between the first end and the pad is made.
 2. The probe of claim 1 wherein a relative movement between the bridging element of the probe device and the pad of the integrated circuit is substantially perpendicular to a plane of the pad.
 3. The probe of claim 1 wherein the plurality of the contact arms have an outward taper.
 4. The probe of claim 1 wherein the plurality of the contact arms have an inward taper.
 5. The probe of claim 1 additionally wherein the second end of each arm comprises a compliant member.
 6. The probe of claim 5 wherein the compliant member provides compliance in a direction parallel to a direction of relative movement between the pad and the bridging element.
 7. The probe of claim 1 additionally wherein the bridging element comprises a compliant member.
 8. The probe of claim 7 wherein the compliant member provides compliance in a direction parallel to a direction of relative movement between the pad and the bridging element.
 9. The probe of claim 7 wherein the compliant member is located adjacent the plurality of arms.
 10. The probe of claim 7 wherein the compliant member is located away from a location where the second end of the arms contact the bridging element.
 11. The probe of claim 1 additionally comprising at least one pushing element that causes the arms to separate as each of the first ends is mated to a pad.
 12. The probe of claim 11 wherein the pushing element operates as a result of a contact between the first end and the pad as the pad and the first end are brought into contact.
 13. The probe of claim 11 wherein the pushing element is capable of being controlled to operate independently of a movement of the contact arms and the pad.
 14. The probe of claim 1 additionally comprising at least one pulling element that causes the arms to come together as each of the first ends is mated to a pad.
 15. The probe of claim 1 wherein the plurality of contact arms are formed from a plurality of adhered layers of deposited material.
 16. The probe of claim 7 wherein the compliant member is formed from a plurality of adhered layers of material.
 17. A probe device for testing integrated circuits, comprising: a bridging element; a plurality of contact arms, each having a first end and a second end, where the second end of each connects to the bridging element and the first end of each is configured to contact a pad of an integrated circuit and wherein at least one of the arms or the bridging element is configured to provide compliance between the probe device and the pad as contact is made.
 18. The probe of claim 17 wherein a relative movement between the bridging element of the probe device and the pad of the integrated circuit is substantially perpendicular to a plane of the pad.
 19. The probe of claim 17 wherein the plurality of the contact arms have an outward taper.
 20. The probe of claim 17 wherein the plurality of the contact arms have an inward taper. 